Aircraft cargo floor



Jam 13, 1953 A. J. LECHNER AIRCRAFT OARGO FLOOR Filed March 22, 1949 mm oN wm INVENTOR.

ALBERT J. LECHNER Agent Patented Jan. 13, 1,953

AIRCRAFT CARGO FLOOR Albert J. Lechner, North Hollywood, Calif., as'- signor to Lockheed Aircraft Corporation, Burbank, Calif.

Application March 22, 1949, Serial No. 82,742

(Cl. S-367.)

6 Claims.

This invention relates to floor construction and relates more particularly to floors for the cargo compartments of airplanes and other vehicles. lt is a general object of the invention to provide a practical, durable and low-cost floor of this character which facilitates the handling, stowage and securing of cargo.

The oors of the cargo compartments of aircraft, and the like, have not been very satisfactory.` In the case of airplanes, it has been the praticeto construct the floors of plywood or 'sheets' Aof aluminum alloy, which are not particularly durable or well suited for the support of concentrated loads. Separate skid rails are often secured to the iloors to facilitate the handling of 'the cargo and large numbers of xed tie-down rings are usually attached to the floor structure so that the cargo may be anchored in place.

Such iioors are high in initial cost and are diiiicult and expensive to repair.

It is an object of the present invention to provide a relatively low-cost floor for aircraft cargo compartments, :and the like, that is serviceable and long wearing and that may be easily and inexpensively repaired. The floor of the invention comprises a plurality of extruded metal sections that are quickly and inexpensively installed and that are strong and long wearing. Furthermore, the individual extruded floor sections may be easily replaced in the event they become worn or broken, thus permitting repair of the floor in the field.

Another object of the invention is to provide a oor of the character referred to in which the extruded metal sections, or at least some of the sections, incorporate integral rails that are available for wheeled dollies and for sliding or skidding the articles of cargo during loading and unloading operations. The skid rails, being formed integral with the oor sections themselves, obviate the necessity for installing separate rails or skids on the oor. This markedly reduces cost of the installation and results in a more durable and practical iioor assembly. Where the rails are elevated slightly above the principal floor surfaces they constitute strong load carrying elements.

A further object of the invention is to provide a oor construction of the character described in which the integral skid rails of the oor sections may valso serve as tie-down means. In accordance with the invention the skid rails are formed or provided with series of spaced openings for the reception of tie-down hooks or rings which are employed to auch@ the Straps.. rapes or other lashings for the cargo. These openings are spaced :along the rails in such a way that the tiedown rings may be advantageously located to secure the particular cargo in the manner desired and the rings m-ay be easily disengaged from the opennigs to leave the rails clear and free When the cargo is to be loaded and unloaded. Thus the integral rails of the floor sections serve not only as tracks for the wheeled dollies and as skids for the cargo, but are also available as hold-down or tie-down means for securing the cargo.

Other objectives and features of the invention will become apparent from the following detailed description throughout which reference will be made to the accompanying drawings wherein:

Figures l is a fragmentary perspective view of an airplane fuselage illustrating the floor of the invention incorporated therein;

Figure 2 is :an enlarged vertical detailed sectional view of the floor assembly illustrating the manner in which a wheeled dolly may operate over the rails and showing a hold-down ring engaged in a rail;

Figure 3 is an enlarged fragmentary vertical sectional view taken substantially as indicated by line 3 3 on Figure 2; and

Figure 4 is an enlarged fragmentary vertical sectional view taken substantially as indicated by line lI- on Figure 2.

The cor construction of the invention has many applications and may be varied considerably to adapt it for given uses, etc. In the drawings, I have shown the floor installed or incorporated in the fuselage of a cargo-type airplane, it being understood that this is only one typical form and application of the invention. The portion of the fuselage I0 illustrated, is shown in a diagrammatic manner and is substantially cylindrical in cross section. Spaced fore and aft beams Il, or the equivalent, are provided in the fuselage I 0 below the oor and the sub-iioor structure includes a plurality of spaced transversals or transverse members I2. These members I2 have horizontal flanges I3 at their upper edges and may have single bulb flanges I4 at -their lower edges secured to the beams H.. The invention is not primarily concerned with the sub-floor structure which obviously may 4Vvary considerably in different aircraft.

The improved oor of the invention may be said to comprise, generally, a plurality of iioor sections I 4 and I5 and integral skid-rails and tie-down rails I6 on the sections I5. y

The floor sections I4 and I5 are preferably extrusions of selected metal, such as an aluminum alloy, magnesium alloy, or steel, and being extrusions are uniform in cross sectional configuration throughout their lengths, it being apparent from an inspection of the drawings that lthe sections I5 are different in cross section than the sections It. The sections Id and I5 preferably extend fore and aft ofthe airplane to have their longitudinal axes substantially normal to the sub-floor transverse members l2. In accordance with the invention, the sections Ill and I5 present or constitute the active iloor elements, serving to drectly support the cargo C. In the form of the invention illustrated, the sections Id and I5 are alternated, that is there is a section I4 then a section I5 arranged parallel with the section It, then a section I4, and so on, with the several adjacent sections arranged in parallel and partially overlapping relation as will be more fully described.

Each floor section I4 has a principal or main web I'i which presents a ilat cargo carrying upper surface. rlhe web I'I of each section It is preferably of substantial width and may be reinforced or supported intermediate its opposite edges by a downwardly projecting strengthening flange I8 which is broadened at its lower edge to bear on the sub-floor members I2. A downwardly and outwardly sloping part IS extends from each longitudinal edge of the main web il, one of said parts being provided with a base flange 28 and the other part I9 having a similar flange 2 E. The base flange 2s is iiat and its under side may rest directly upon the transverse sub-floor members I2. The flange 2i, which extends along the opposits longitudinal edge of the section itl, lies in a plane parallel with and slightly above the plane of the flange 20 to lap over a portion of the adjacent floor section I5, as described below. Because the sections 4 are extrusions, the parts just described extend uniformly throughout the lengths of the sections.

The :door sections I5 each include a main web 22 resembling but preferably somewhat narrower than the webs I'I of the sections I4. The upper sides of the webs 22 form iloor surfaces and lie in the same plane as the upper surfaces of the adjacent webs I'I'. Thus the top surfaces of the webs II and 22 of the alternated door sections I4 and I5 constitute the primary floor surfaces. Downwardly and outwardly sloping parts 23 extend from the opposite margins of the web 22 of each section I5. One of these parts 23 carries at its lower end an outwardly extending flange 24 which engages or laps under the flange 2I of the adjacent section I4. Suitable fastening devices extend through aligned openings in the overlapping flanges 2I and 24 and the flanges i3 of the transverse members I2 to assist in securing the oor sections to the sub-struc- 'J ture. I have shown countersunk or flush-head screws 25 passing through openings in the flanges I3, 2l and 24 and provided with appro priate nuts. Rows of the screws 25 also connect the flanges 2| and 24 between the spaced transversals I2 to secure the floor sections together thoughout their lengths. The sloping parts 23 on the opposite edges or sides of the sections I5 have outwardly extending flanges 25 whose lower sides bear directly on the sub-floor members I2. Screws 21, similar to the screws 25, secure the flanges 26 to the members I2. The base flanges 26 are of substantial width to carry the rails VI5 and their outer edge portions are formed to overlap the flanges 20 of the adjacent floor sections I4. The marginal portions 28 of the flanges 26 are raised or stepped upwardly to lap over the flanges 2) and bolts or screws 29 are passed through openings in the overlapping flanges and the flanges I3 of the members I2 to assist in securing the door sections to the sub-structure. Rows of screws 9 are passed lthrough openings in the overlapping flanges 28 and 2G to secure the sections ld and I5 together between the spaced transversais I2 and throughout the length of the floor sections.

The rails It, which are features of the invention, extend along one margin of each floor section I5 projecting upwardly from its flange The rails I6 are integral with the sections i5, being continuous integral parts of the extrusions. rIhe rails I6 may resemble railroad rails having vertical webs 30 and broadened heads 3i. The height of the rails 3l! may be different in given installations of the floor. Where it is intended to use wheeled dollies extensively and to slide or skid the articles of cargo to a minimum extent, the upper surfaces of the rail It may either be flush with or below the surfaces of the webs il and 22. In such cases the top surfaces of the rails l supplement the surfaces of the webs I? and 22 as floor faces and load carrying parts, In other instances, the top surfaces of the rails l2 may be slightly above the planes of the webs il and 22 so that the rails are available to assist in sliding or skidding the cargo about as well as serving as tracks for the wheels W of the dolly D. The drawings illustrate the tops of the rails i6 as occupying a plane slightly above the plane of the webs I' and 22, it being understood that this is only one manner of forming Ithe rails. The webs 32 of the rails It project upwardly sub stantially mid-way between the margins of the anges 2li to be adequately spaced between the raised parts of the adjacent oor sections ifi and I5. Where the rails I6 are provided on correspending edges of the spaced apart floor sections i5 as illustrated, the spacing of the track-rails is suitable for the wheels W of the dolly D.

As mentioned above, the rails IG are provided with openings 32 to receive tie-down rings or the like. Thus, as best illustrated in Figures 2 and 4, the web 30 of each rail I6 has a plurality of spaced openings 32. The openings 32 are preferably spaced throughout the length of the rails I8 so as to be available for the reception of rings 33 and the like to hold down the cargo at any point on the floor. rIhe openings 32 are preferably located in the webs 3i! at the bases of the rail heads 3l so that the hold-down rings 33 may enga-ge under or cooperate with the heads. As illustrated, the under sides of the heads 3i and the lower arms of the rings or hooks 33 have corresponding or mating radii of curvature so that the rings may swivel or turn on the rail head surfaces to assume practically any required angle` One side of each ring 33 is open at Ell to permit ready engagement of the rings in the rail openings S2 and easy intentional removal of the rings from the openings. The upper arms or parts of the rings 33 are shaped to receive and dependably retain the fittings of the cargo straps S or the like. it will be apparent how the clips or rings 23 may be engaged in any selected openings 32 of the several rails it to receive the straps S, or the like, to secure the articles of cargo in various locations throughout the floor.

When it is intended that the aircraft carry wet cargo, or if it is desired to periodically wash down the floor, the several joints of the floor assembly may be sealed to make the same watertight. Thus I have shown sealing compound sealing the joints between the flanges 2l and 24 and the flanges 26 and 28. Where the ends of aligned sections I4 and l5 adjoin, I provide sealing clips 36 at the under sides of the sections. The clips 36 may be of metal and are preferably secured to only one section of each pair of the adjoining floor sections by rivets 37 or the like, as shown in Figure 3, However, when the floor assembly is designed or intended to assume a portion of the primary structural loads of the airplane, the clips 36 may be relatively strong and heavy and are secured to each of the adjoining sections to structurally connect the floor sections. Sealing compound 35 is provided in the gaps or spaces between the adjacent ends of the sectionsv I4 and i5 and is held against displacement by the clips.

From the foregoing detailed description it will be seen that IA have provided a simple inexpensive cargo floor that is practical and long wearing. In the event of breakage or the like of one of the sections I4 or I5, the screws 25, 2l and/or 29 of that section are removed and the screws of an adjacent section are loosened to permit removal of the broken or worn section and insertion of a replacement floor section. The floor is relatively light-weight and the fore and aft extending metal sections I4 and I5 may' assist in assuming some of the primary bending loads of the fuselage. The rails I6, formed as integral parts of the floor sections l5, materially assist in the handling of the cargo by serving as tracks or skids and also constitute well-distributed tiedown anchors. It is contemplated that the rails I6 be spaced and related so that they may be employed as hold-down means for seats, litters.

and other airplane fittings and accessories. As the rails I6 extend throughout the floor assembly they are readily available for such purposes.

Having described only a typical form of the invention, I do not wish to be limited to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art and/or fall within the scope of the following claims.

I claim:

1. A floor assembly for use upon a sub-structure on a cargo vehicle, comprising a plurality of elongate floor sections arranged in parallel relation, each section comprising a horizontal web-portion, two longitudinally-extending downwardly-projecting side portions at the lateral edges of said web portion and two longitudinallyextending, horizontal edge flanges along the longitudinal bottom edges of said side portions, said horizontal web portions all lying in the same plane, and the adjacent side portions of adjacent floor sections being spaced apart, and longitudinally extending rails arranged parallel to said floor sections and disposed between adjacent side portions of adjacent floor sections, each of said rails having a vertical web portion and a head portion, the web portions of the rails being spaced from the adjacent side portions of the floor sections to provide channels for flanged wheels to roll on the head portions of said rails, said web portions of the rails having means below the plane of said horizontal web portions to cooperate with cargo hold-down means.

2. A floor assembly for use upon a sub -structure on a cargo vehicle, comprising a plurality of elongate floor sections arranged in parallel relation, each section comprising a horizontal web portion, two longitudinally-extending downwardly-projecting side portions at the lateral edges of said web portion and two longitudinallyextending horizontal edge flanges along the longiitudinal bottom edges of said side portions, said horizontal web portions all' lying in the same plane and the adjacent side portions of adjacent floor sections being spaced apart, and longitudinally-extending rails of general I-shape in cross-section integral with and projecting vertically upwardly from at least some of said flanges between adjacent side portions of adjacent floor sections, said rails being longitudinally parallel to said floor sections and the web portions of said rails being spaced from the adjacent side portions of the floor sections to'provide channels for flanged wheels to roll on the heads of said rails, and the web portions of said rails having longitudinally-spaced openings therein below the plane of said horizontal web portions to receive cargo hold-down hooks. l

3. A floor assembly fr use upon a sub-structure on a cargo vehicle, comprising a plurality of elongate floor sections arranged in parallel relation, each section comprising a horizontal web portion, two longitudinally-extending downwardly-projecting side .portions at the lateral edges of said web portion and two longitudinallyextending horizontal edge flanges along the longitudinal bottom edges of said side portions, said horizontal web portions all lying in the same plane and the adjacent side portions of adjacent floor sections being spaced apart, and longitudinally-extending rails of general I-shape in cross-section integral with and projecting vertically upwardly from at least some of said flanges between adjacent side portions of adjacent floor sections, said rails being longitudinally parallel to said floor sections and the web portions of said rails being spaced from the adjacent side portions of the floor sections to provide channels for flanged wheels to roll on the heads of said rails, the web portions of said rails having longitudinally-spaced openings therein below the plane of said horizontal web portions to receive cargo hold-down hooks, and the under sides of the rail heads being convex to cooperate with said hooks.

4. A floor assembly for use upon a sub-structure on a cargo vehicle, comprising a plurality cf elongate floor sections arranged in parallel relation, each section comprising a horizontal web portion, two longitudinally-extending downwardly-projecting side portions at the lateral edges of said web portion and two longitudinallyextending horizontal edge flanges along the longitudinal bottom edges of said side portions, said horizontal web portions all lying in the same plane, some of said floor sections having downwardly projecting strengthening flanges between their side portions adapted to seat upon said substructure, and others of said floor sections having longitudinally-extending rails integral with and projecting vertically upwardly from at least one of their edge flanges, said rails extending longitudinally parallel to the floor sections and having web portions and head portions, the web portion of each rail being spaced from the adjacent side portions of the floor sections to provide channels for flanged wheels to roll on the head portions of said rails, and the web portions of said rails having longitudinally-spaced openings therein to receive cargo hold-down hooks.

5. A floor assembly for use upon a sub-structure on a cargo vehicle, comprising `a plurality of elongate floor sections arranged in parallel relaportino, twoA 19neiiudineliyf-exiendine down,- wardwngroieeiine Side. Portiens at the lateral edges ofysaidlweb, portionandtwo longitudinallyextending.- horizontalY edge flanges 'along the longitudinal bottom edges of said side` portions, saidhorizontalweb portions all lying in the same pl ane some of said floor' sections having downwardly projecting, strengthening anges between their side, portions adapted, to seat upon said substructureand alternate oor sections having longitudinallyextending rails integral with and projectingv vertically upwardly from at least one of theiredge flanges, said rails extending longitudinally parallel to the floor sections and having web portions and head portions, the web portion of each rail. being spaced from the adjacent side portions; of the iioor sections to provide channels for VIianged wheel to roll on thehead portions of said rails, and the Web portions of said rails f extendinghorizontaledge iianges along the longitudinal bottom edges.` of saidv side portions, said horizontal web portions all lying in the same pla-ne and the adjacent side portions of adjacent floor sections being spaced apart, alternate edge 8 inneemt theflooesetiisOyellappme and, beine Ove leaned bn respeeiivel'y, tliedicent ed@ Ganges 0f' theffleerleetops; the Overlapping p01- tio. .s Qi @le @dee fleoeeshaing registering penioesthmuee when sec'urinemansmay harassed te fasten. the, flowi- Sectieesfto Said, Sublstliiefurn and longitudinally extending rails disposed. b etween adjacent side,portions o f at least some of the.. adjacent fioor seclztiornlsk to extend parallelv to saidiioor sections, each of saidrails havingv ahead Portieri and', a.' vereally extending web portion. the Webfeotien. Qt each, rail beine spaced, from the; adiacente Side Portions @fr the floor Sections to proyide chan,n elzls` for'anged Wheels to roll on the head portie of said rails, and the Webpor-Y tion` of ease rail; haring longitudinally spaced means thereon below.- the 'plane of the horizontal web portions or: the, floor" sections! by Awhich to secure cargohold-down hooks te said rails? A.LBERTV J- LEC-HNER.

@aimerions @Irren l.he following references are of record in the. Iiie of: this patent:

UNITED STA'TIllS PATENTS Date, 

